Study of respiratory symptoms among sputum positive

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On the other hand, false negative acid-fast smear may be due to
inadequate. Collection of sputum, Storage ofspecimen, Preparation ofthe
smear, Staining of slides and Examination ofthe smears.
2) Cultivating M. TB
The definitive diagnosis of mycobacterial disease demands that the
causative agent be recovered on culture medium, and identified by using a
number ofdifferential in vitro tests.(Zheng and Roberts, 1999)
Kent and Kubica, (1985), defined The ideal medium for isolation of
mycobacterial should:
I) Support rapid and luxuriant growth of small numbers ofmycobacteria
2) Permit preliminary differentiation of isolates on the basis ofpigment
production and colony morphology.
3) Inhibit the growth ofcontaminants.
4) Be economical and simple to prepare from readily available ingredients
and
5) Enable the performance of drug susceptibility tests
Many different media are available for cultivating mycobacteria, most
are variations of either egg-potato base (Lowenstein-Jensen Medium and
American Thoracic Society Medium) or serum agar base (Middle Brook
7HIO and 7HII) media. Each medium has advantages and disadvantages,
,.f.l and they compliment each other, the advantages ofegg media as L.T media
are that, they can be stored in refrigerator for several months, less likely to
become contaminated during preparation, and also yield a greater number
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